Receive and Transmit Description

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IP Hdr

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Fragment

 

 

 

 

 

 

 

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Header Checksum

Layer 4 Protocol ID

Time to Live

Source Address

Destination Address

Options

Figure 3-9. IPv4 Header (Little-Endian Order)

Flags Field Definition:

The Flags field is defined below. Note that hardware does not evaluate or change these bits.

MF

More Fragments

NF

No Fragments

Reserved

Note: The IPv6 header is first shown in the traditional (RFC 2460), big-endian representation. The actual data is fetched from memory in little-endian format.

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Traffic Class

 

 

 

 

 

 

 

 

 

 

Flow Label

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Payload Length

 

 

 

 

 

 

Next Header

 

 

 

 

 

 

Hop Limit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Source Address

Destination Address

Figure 3-10. IPv6 TCP Header (Traditional Representation)

A TCP or UDP frame uses a 16 bit wide one’s complement checksum. The checksum word is computed on the outgoing TCP or UDP header and payload, and on the Pseudo Header. Details on checksum computations are provided in Section 3.5. TCP requires the use of checksum, where it is optional for UDP.

Software Developer’s Manual

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Page 75
Image 75
Intel PCI-X manual Type of service Version IP Hdr Length Fragment, Fragment Offset Low, Offset High Header Checksum